How can I delete all submissions of a form?

how do i delete all submissions but not the form, the "delete all submission" button does not work, it says I have to reenter my user and password

This is the normal behavior of the "delete all submissions" button since we need to verify that the account owner is actually doing this and also to confirm that you really want to proceed because once the submissions are deleted there's no way to retrieve them.

If you're sure that you want to continue, please enter the requested credentials and your submissions should be deleted once you've entered them.

Let us know if you're still unable to complete this procedure.
Thanks.